IG: don't produce code that can't compile in foreach quick fixes (IDEA-114183)

plugins/InspectionGadgets/src/com/siyeh/ig/migration/ForCanBeForeachInspection.java

@@ -14,6 +14,7 @@ import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
 import com.intellij.util.ArrayUtil;
+import com.intellij.psi.util.TypeConversionUtil;
 import com.siyeh.HardcodedMethodConstants;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
@@ -1211,37 +1212,30 @@ public class ForCanBeForeachInspection extends BaseInspection {
       if (!(declaredIterator instanceof PsiVariable)) {
         return null;
       }
-      final PsiVariable iteratorVariable = (PsiVariable)declaredIterator;
-      final PsiMethodCallExpression initializer =
-        (PsiMethodCallExpression)iteratorVariable.getInitializer();
+      final PsiVariable iterator = (PsiVariable)declaredIterator;
+      final PsiMethodCallExpression initializer = (PsiMethodCallExpression)iterator.getInitializer();
       if (initializer == null) {
         return null;
       }
-      final PsiType iteratorType = initializer.getType();
-      if (iteratorType == null) {
+      final PsiReferenceExpression methodExpression = initializer.getMethodExpression();
+      final PsiExpression collection = ExpressionUtils.getQualifierOrThis(methodExpression);
+      final PsiType collectionType = collection.getType();
+      if (collectionType == null) {
         return null;
       }
-      final PsiType iteratorContentType = getContentType(iteratorType, CommonClassNames.JAVA_UTIL_ITERATOR);
-      final PsiType iteratorVariableType = iteratorVariable.getType();
-      final PsiType contentType;
-      final PsiClassType javaLangObject = TypeUtils.getObjectType(forStatement);
+      final PsiType contentType = getContentType(collectionType, CommonClassNames.JAVA_LANG_ITERABLE);
+      if (contentType == null) {
+        return null;
+      }
+      PsiType iteratorContentType = getContentType(iterator.getType(), CommonClassNames.JAVA_UTIL_ITERATOR);
+      if (TypeUtils.isJavaLangObject(iteratorContentType)) {
+        iteratorContentType = getContentType(initializer.getType(), CommonClassNames.JAVA_UTIL_ITERATOR);
+      }
       if (iteratorContentType == null) {
-        final PsiType iteratorVariableContentType =
-          getContentType(iteratorVariableType, CommonClassNames.JAVA_UTIL_ITERATOR);
-        if (iteratorVariableContentType == null) {
-          contentType = javaLangObject;
-        }
-        else {
-          contentType = iteratorVariableContentType;
-        }
+        return null;
       }
-      else {
-        contentType = iteratorContentType;
-      }
-      final PsiReferenceExpression methodExpression =
-        initializer.getMethodExpression();
-      final PsiExpression collection = ExpressionUtils.getQualifierOrThis(methodExpression);
-      final boolean isDeclaration = isIteratorNextDeclaration(firstStatement, iteratorVariable, contentType);
+
+      final boolean isDeclaration = isIteratorNextDeclaration(firstStatement, iterator, contentType);
       final PsiStatement statementToSkip;
       @NonNls final String finalString;
       final String contentVariableName;
@@ -1285,7 +1279,7 @@ public class ForCanBeForeachInspection extends BaseInspection {
         }
         statementToSkip = null;
       }
-      final String contentTypeString = contentType.getCanonicalText();
+      final String contentTypeString = iteratorContentType.getCanonicalText();
       @NonNls final StringBuilder out = new StringBuilder();
       out.append("for(");
       out.append(finalString);
@@ -1293,12 +1287,12 @@ public class ForCanBeForeachInspection extends BaseInspection {
       out.append(' ');
       out.append(contentVariableName);
       out.append(": ");
-      if (!contentType.equals(javaLangObject) && iteratorContentType == null) {
+      if (!TypeConversionUtil.isAssignable(iteratorContentType, contentType)) {
         out.append('(').append("java.lang.Iterable<").append(contentTypeString).append('>').append(')');
       }
       out.append(collection.getText());
       out.append(')');
-      replaceIteratorNext(body, contentVariableName, iteratorVariable, contentType, statementToSkip, out);
+      replaceIteratorNext(body, contentVariableName, iterator, contentType, statementToSkip, out);
       return out.toString();
     }
 

plugins/InspectionGadgets/src/com/siyeh/ig/migration/WhileCanBeForeachInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2015 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2018 Dave Griffith, Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -130,8 +130,10 @@ public class WhileCanBeForeachInspection extends BaseInspection {
       if (contentType == null) {
         return;
       }
-      final PsiType iteratorType = iterator.getType();
-      final PsiType iteratorContentType = ForCanBeForeachInspection.getContentType(iteratorType, "java.util.Iterator");
+      PsiType iteratorContentType = ForCanBeForeachInspection.getContentType(iterator.getType(), CommonClassNames.JAVA_UTIL_ITERATOR);
+      if (TypeUtils.isJavaLangObject(iteratorContentType)) {
+        iteratorContentType = ForCanBeForeachInspection.getContentType(initializer.getType(), CommonClassNames.JAVA_UTIL_ITERATOR);
+      }
       if (iteratorContentType == null) {
         return;
       }
@@ -162,9 +164,10 @@ public class WhileCanBeForeachInspection extends BaseInspection {
       if (JavaCodeStyleSettings.getInstance(whileStatement.getContainingFile()).GENERATE_FINAL_PARAMETERS) {
         out.append("final ");
       }
-      out.append(iteratorContentType.getCanonicalText()).append(' ').append(contentVariableName).append(": ");
+      final String canonicalText = iteratorContentType.getCanonicalText();
+      out.append(canonicalText).append(' ').append(contentVariableName).append(": ");
       if (!TypeConversionUtil.isAssignable(iteratorContentType, contentType)) {
-        out.append("(java.lang.Iterable<").append(iteratorContentType.getCanonicalText()).append(">)");
+        out.append("(java.lang.Iterable<").append(canonicalText).append(">)");
       }
       out.append(collection.getText());
       out.append(')');
@@ -185,7 +188,7 @@ public class WhileCanBeForeachInspection extends BaseInspection {
           break;
         }
         final PsiExpression expression = assignment.getRExpression();
-        PsiTypeElement typeElement = iterator.getTypeElement();
+        final PsiTypeElement typeElement = iterator.getTypeElement();
         if (typeElement.isInferredType() &&
             (expression == null || 
              PsiType.NULL.equals(expression.getType()) || 

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/for_can_be_foreach/RawCollection.after.java

@@ -0,0 +1,11 @@
+import java.util.Iterator;
+import java.util.List;
+
+class RawCollection {
+
+  void m2(List ss) {
+      for (String s : (Iterable<String>) ss) {
+          "".split(s);
+      }
+  }
+}

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/for_can_be_foreach/RawCollection.java

@@ -0,0 +1,12 @@
+import java.util.Iterator;
+import java.util.List;
+
+class RawCollection {
+
+  void m2(List ss) {
+    <caret>for (Iterator<String> iterator = ss.iterator(); iterator.hasNext();) {
+      String s = iterator.next();
+      "".split(s);
+    }
+  }
+}

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/while_can_be_foreach/RawIterator.after.java

@@ -0,0 +1,13 @@
+package com.siyeh.igfixes.migration.while_can_be_foreach;
+
+import java.util.Iterator;
+import java.util.List;
+
+class RawIterator implements Iterable {
+
+  void m(List<String> ss) {
+      for (String s : ss) {
+          System.out.println(s);
+      }
+  }
+}

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/while_can_be_foreach/RawIterator.java

@@ -0,0 +1,14 @@
+package com.siyeh.igfixes.migration.while_can_be_foreach;
+
+import java.util.Iterator;
+import java.util.List;
+
+class RawIterator implements Iterable {
+
+  void m(List<String> ss) {
+    final Iterator iterator = ss.iterator();
+    while<caret> (iterator.hasNext()) {
+      System.out.println(iterator.next());
+    }
+  }
+}

plugins/InspectionGadgets/testsrc/com/siyeh/ig/fixes/migration/ForCanBeForeachFixTest.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.siyeh.ig.fixes.migration;
 
 import com.intellij.application.options.CodeStyle;
@@ -44,6 +30,7 @@ public class ForCanBeForeachFixTest extends IGQuickFixesTestCase {
       settings.FIELD_NAME_PREFIX = oldPrefix;
     }
   }
+  public void testRawCollection() { doTest(); }
 
   @Override
   public void setUp() throws Exception {

plugins/InspectionGadgets/testsrc/com/siyeh/ig/fixes/migration/WhileCanBeForeachFixTest.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.siyeh.ig.fixes.migration;
 
 import com.intellij.pom.java.LanguageLevel;
@@ -35,6 +21,7 @@ public class WhileCanBeForeachFixTest extends IGQuickFixesTestCase {
   public void testUnboundWildcard() { doTest(); }
   public void testVarWithoutValidInitializer() { doTest(); }
   public void testVarWithValidInitializer() { doTest(); }
+  public void testRawIterator() { doTest(); }
 
   @Override
   protected void tuneFixture(JavaModuleFixtureBuilder builder) {